Oled package structure and packaging method

ABSTRACT

An OLED packaging method includes providing a substrate on which an OLED device is formed and a package lid that comprises a trough formed to correspond to the OLED device and receive a solid resin film therein, forming a loop of fritted glass on the package lid and outside the trough, forming a loop of inorganic protective frame made of silicon nitride on the substrate and at a location that is outside the trough and inside the fritted glass, forming a loop of adhesive on the package lid to correspond to the inorganic protective frame, and laminating the package lid and the substrate to each other such that the OLED device is covered by the solid resin film and the inorganic protective frame is adhered to the adhesive to form a combined circumferential wall, which surrounds, together with the fritted glass, the OLED device covered by the solid resin film.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of co-pending patent application Ser.No. 14/429,348, filed on Mar. 18, 2015, which is a national stage of PCTapplication number PCT/CN2015/072598, filed on Feb. 9, 2015, claimingforeign priority of Chinese patent application number 201410833403.4,filed on Dec. 26, 2014.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to the field of packaging technology, andin particular to an OLED (Organic Light-Emitting Diode) packagestructure and a packaging method.

2. The Related Arts

OLED stands for organic light emitting diode, which has variousadvantages, such as being self-luminous, high brightness, wide viewangle, high contrast, being flexible, and low power consumption and isconsidered the new generation of display measures that gradually takesthe place of the conventional liquid crystal displays by being widelyused in mobile phone screens, computer displays, and full-colortelevisions. The OLED displaying technology is different from the liquidcrystal displaying technology in that no backlighting is needed and anextremely thin coating layer of an organic material and a glasssubstrate are used in such a way that when an electrical current flowstherethrough, the organic material emits light. However, since theorganic material is highly reactive to moisture and oxygen, an OLEDdisplay, which is a display device based on such an organic material,must require extremely high standard of packaging.

Most of the organic substances contained in an OLED light emission layerare extremely sensitive to pollutions, oxygen, and moisture contained inthe atmosphere. Electrochemical corrosion may readily occur in a humidenvironment so as to severely affect the lifespan of an OLED device.Interior sealability of an OLED device must be improved by means ofdevice packaging in order to achieve isolation from the outsideenvironment as better as possible. This is of vital importance to thestability of light emission of an OLED device.

Packaging of an OLED device is generally achieved with a frit basedlaser packaging process as illustrated in FIG. 1. Such a packagingprocess is carried out by forming a loop of fritted glass 300 around acircumference of a package lid 200, which is then positioned on asubstrate 100 on which an OLED device 400 to be packaged is arranged. Alaser is then applied to instantaneously heat the fritted glass 300 tomelt thereby adhering the two glass sheets together. Frit based lasertechnology involves an inorganic packaging medium so as to exhibits astrong capability of blocking moisture and oxygen and a device soobtained has an extended lifespan, making it particularly suitable forthe OLED technology that is generally sensitive to moisture and oxygen.However, the frit based laser packaging process generally needs the gapof a cavity to be large, making it impossible to provide a sufficientmechanical strength and thus not suitable for OLED display panels oflarge sizes. Further, thermal radiation occurs when the fritted glass isbeing molten and this may cause burning of a light emission element.

Thus, it is desired to provide a novel OLED package structure and apackaging method that overcome the above problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an OLED packagestructure, which has an excellent capability of blocking moisture andoxygen and provides an excellent packaging effect and shows a relativelyhigh mechanical strength so as to be suitable for a large-sized OLEDdisplay panel.

Another object of the present invention is to provide an OLED packagingmethod, which involves a simple process, is easy to perform, has anexcellent packaging effect, has an excellent capability of blockingmoisture and oxygen, and also has a small gap inside a sealed object soas to provide a relatively high mechanical strength and is thus suitablefor a large-sized OLED display panel.

To achieve the above objects, the present invention provides an OLEDpackage structure, which comprises a substrate, a package lid oppositeto the substrate, an OLED device located between the substrate and thepackage lid and mounted on the substrate, a solid resin film locatedbetween the substrate and the package lid and arranged on the packagelid to completely cover the OLED device, an inorganic protective framearranged on the substrate and located outside an outer circumference ofthe solid resin film, adhesive applied on the package lid to bond theinorganic protective frame and the package lid to each other, andfritted glass arranged outside an outer circumference of the inorganicprotective frame to bond the substrate and the package lid to eachother.

The package lid comprises a trough formed therein to correspond inposition to the OLED device and the solid resin film is adhesivelymounted inside the trough in such a way as to completely cover the OLEDdevice.

The substrate is a thin-film transistor (TFT) substrate and the packagelid comprises a glass board or a metal board.

The inorganic protective frame is made of a material comprising siliconnitride.

The adhesive comprises box dam glue.

The present invention also provides an OLED packaging method, whichcomprises the following steps:

(1) provides providing a substrate 1 to be package and a package lid,

wherein the package lid comprises a trough formed therein;

(2) coating a loop of frit along a circumference of the package lidoutside the trough and applying high temperature pre-sintering to formfritted glass;

(3) forming a loop of inorganic protective frame on the substrate at alocation outside the trough and corresponding an inner side of thefritted glass;

(4) forming an OLED device on an internal location of the substratecorresponding to the trough of the package lid;

(5) adhesively attaching a solid resin film inside the trough of thepackage lid;

(6) forming a loop of adhesive on the package lid at a locationcorresponding to the inorganic protective frame;

(7) laminating the substrate and the package lid to each other to havethe substrate and the package lid bonded to each other by means of thesolid resin film and the adhesive; and

(8) applying irradiation of laser to melt the fritted glass so as tohave the package lid and the substrate further bonded together tocomplete packaging of the substrate with the package lid.

The substrate is a TFT substrate and the package lid comprises a glassboard or a metal board.

In step (3), the inorganic protective frame is made of a materialcomprising silicon nitride and the inorganic protective frame has aheight smaller than a height of the fritted glass.

The solid resin film has a surface area greater than a surface area ofthe OLED device so that when the substrate and the package lid arelaminated to each other, the solid resin film completely covers the OLEDdevice.

In step (6), the adhesive comprises box dam glue.

The present invention further provides an OLED package structure, whichcomprises a substrate, a package lid opposite to the substrate, an OLEDdevice located between the substrate and the package lid and mounted onthe substrate, a solid resin film located between the substrate and thepackage lid and arranged on the package lid to completely cover the OLEDdevice, an inorganic protective frame arranged on the substrate andlocated outside an outer circumference of the solid resin film, adhesiveapplied on the package lid to bond the inorganic protective frame andthe package lid to each other, and fritted glass arranged outside anouter circumference of the inorganic protective frame to bond thesubstrate and the package lid to each other;

wherein the package lid comprises a trough formed therein to correspondin position to the OLED device and the solid resin film is adhesivelymounted inside the trough in such a way as to completely cover the OLEDdevice; and

wherein the substrate is a thin-film transistor (TFT) substrate and thepackage lid comprises a glass board or a metal board.

The efficacy of the present invention is that the present inventionprovides an OLED package structure, which comprises an inorganicprotective frame arranged inboard the fritted glass so as to effectivelystrengthen air tightness of the fritted glass and a solid resin filmarranged on a package lid to cover an OLED device so as to furtherstrengthen the capability of blocking moisture and at the same lessen agap in the interior of the sealed object thereby improving mechanicalstrength thereof and extending the lifespan and thus making it suitableto a panel of a large size. The present invention provides an OLEDpackaging method, in which by arranged an inorganic protective frame onan inner side of and, thus, inboard fritted glass, air tightnessachieved with the fritted glass is effectively strengthened. Further, asolid resin film is arranged on a package lid to cover an OLED device soas to further strengthen the capability of blocking moisture. Further,the inorganic protective frame helps isolate radiation heat generated insintering the fritted glass thereby protecting a light emission elementfrom being burned and also, a gap in the interior of the sealed objectis lessened to provide a sufficient mechanical strength and thuseffectively extend the lifespan of the OLED device, making it suitablefor a panel of a large size and easy to carry out with improvedoperability.

For better understanding of the features and technical contents of thepresent invention, reference will be made to the following detaileddescription of the present invention and the attached drawings. However,the drawings are provided for the purposes of reference and illustrationand are not intended to impose limitations to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution, as well as other beneficial advantages, of thepresent invention will be apparent from the following detaileddescription of an embodiment of the present invention, with reference tothe attached drawing.

In the drawing:

FIG. 1 is a cross-sectional view showing a conventional OLED (OrganicLight-Emitting Diode) package structure;

FIG. 2 is a cross-sectional view showing an OLED package structureaccording to the present invention;

FIG. 3 is a flow chart illustrating an OLED packaging method accordingto the present invention;

FIG. 4 is a schematic view illustrating step 1 of the OLED packagingmethod according to the present invention;

FIG. 5 is a schematic view illustrating step 2 of the OLED packagingmethod according to the present invention;

FIG. 6 is a schematic view illustrating step 3 of the OLED packagingmethod according to the present invention;

FIG. 7 is a schematic view illustrating step 4 of the OLED packagingmethod according to the present invention;

FIG. 8 is a schematic view illustrating step 5 of the OLED packagingmethod according to the present invention;

FIG. 9 is a schematic view illustrating step 6 of the OLED packagingmethod according to the present invention;

FIG. 10 is a schematic view illustrating step 7 of the OLED packagingmethod according to the present invention; and

FIG. 11 is a schematic view illustrating step 8 of the OLED packagingmethod according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To further expound the technical solution adopted in the presentinvention and the advantages thereof, a detailed description is given toa preferred embodiment of the present invention and the attacheddrawings.

Referring to FIG. 2, the present invention provides an organiclight-emitting diode (OLED) package structure, which comprises asubstrate 1, a package lid 2 opposite to the substrate 1, an OLED device12 located between the substrate 1 and the package lid 2 and mounted onthe substrate 1, a solid resin film 22 located between the substrate 1and the package lid 2 and arranged on the package lid 2 to completelycover the OLED device 12, an inorganic protective frame 11 arranged onthe substrate 1 and located outside an outer circumference of the solidresin film 22, adhesive 23 applied on the package lid 2 to bond theinorganic protective frame 11 and the package lid 2 to each other, andfritted glass 21 arranged outside an outer circumference of theinorganic protective frame 11 to bond the substrate 1 and the packagelid 2 to each other.

Further, the package lid 2 comprises a trough 20 formed therein tocorrespond in position to the OLED device 12. The solid resin film 22 isadhesively mounted inside the trough 20 in such a way as to completelycover the OLED device 12.

The substrate 1 can be a thin-film transistor (TFT) substrate. Thepackage lid 2 can be a glass board or a metal board and when it is ametal board, it is made of an alloy material. Preferably, the packagelid 2 is a glass board.

Preferably, the inorganic protective frame 11 is made of a materialcomprising silicon nitride.

Specifically, the inorganic protective frame 11 has a height that isslightly smaller than a height of the fritted glass 21. The arrangementof the inorganic protective frame 11 helps strengthen air tightness ofthe fritted glass 21 so as to enhance the capability of blockingmoisture and oxygen and also to isolate thermal radiation induced insintering the fritted glass 21 thereby protecting a light emissionelement from being burned.

The adhesive 23 can be box dam glue.

In the above OLED package structure, the inorganic protective frame isarranged on an inner side of and, thus, inboard the fritted glass toeffectively strengthen air tightness achieved with the fritted glass.Further, the solid resin film is arranged on the package lid to coverthe OLED device so as to further strengthen the capability of blockingmoisture and at the same lessen a gap in the interior of the sealedobject thereby improving mechanical strength thereof and extending thelifespan and thus making it suitable to a panel of a large size.

Referring to FIG. 3, the present invention also provides an OLEDpackaging method, which comprises the following steps:

Step 1: as shown in FIG. 4, providing a substrate 1 to be package and apackage lid 2.

The substrate 1 can be a TFT substrate. The package lid 2 can be a glassboard or a metal board and when it is a metal board, it is made of analloy material. Preferably, the package lid 2 is a glass board.

The package lid 2 comprises a trough 20 formed therein.

Step 2: as shown in FIG. 5, coating a loop of frit along a circumferenceof the package lid 2 outside the trough 20 and applying high temperaturepre-sintering to form fritted glass 21.

Step 3: as shown in FIG. 6, forming a loop of inorganic protective frame11 on the substrate 1 at a location outside the trough 20 andcorresponding an inner side of the fritted glass 21.

Specifically, the inorganic protective frame 11 is made of a materialcomprising silicon nitride. The inorganic protective frame 11 has aheight that is slightly smaller than a height of the fritted glass 21.The arrangement of the inorganic protective frame 11 helps strengthenair tightness of the fritted glass 21 so as to enhance the capability ofblocking moisture and oxygen and also to isolate thermal radiationinduced in sintering the fritted glass 21 thereby protecting a lightemission element from being burned.

Step 4: as shown in FIG. 7, forming an OLED device 12 on an internallocation of the substrate 1 corresponding to the trough 20 of thepackage lid 2.

Specifically, vapor deposition is applied to make the OLED device 12.

Step 5: as shown in FIG. 8, adhesively attaching a solid resin film 22inside the trough 20 of the package lid 2.

Specifically, the solid resin film 22 has a surface area that is greaterthan a surface area of the OLED device 12 to be packaged so that whenthe substrate 1 and the package lid 2 are laminated to each other, thesolid resin film 22 completely covers the OLED device 12. The solidresin film 22 provides resistance to moisture so as to further improvethe capability of blocking moisture.

Step 6: as shown in FIG. 9, forming a loop of adhesive 23 on the packagelid 2 at a location corresponding to the inorganic protective frame 11.

Preferably, the adhesive 23 is box dam glue.

Step 7: as shown in FIG. 10, laminating the substrate 1 and the packagelid 2 to each other to have the substrate 1 and the package lid 2 bondedto each other by means of the solid resin film 22 and the adhesive 23.

Step 8: as shown in FIG. 11, applying irradiation of laser to melt thefritted glass 21 so as to have the package lid 2 and the substrate 1further bonded together to complete packaging of the substrate 1 withthe package lid 2.

In the above OLED packaging method, by arranged the inorganic protectiveframe on an inner side of and, thus, inboard the fritted glass, airtightness achieved with the fritted glass is effectively strengthened.Further, the solid resin film is arranged on the package lid to coverthe OLED device so as to further strengthen the capability of blockingmoisture. Further, the inorganic protective frame helps isolateradiation heat generated in sintering the fritted glass therebyprotecting a light emission element from being burned and also, a gap inthe interior of the sealed object is lessened to provide a sufficientmechanical strength and thus effectively extend the lifespan of the OLEDdevice, making it suitable for a panel of a large size and easy to carryout with improved operability.

In summary, the present invention provides an OLED package structure,which comprises an inorganic protective frame arranged inboard thefritted glass so as to effectively strengthen air tightness of thefritted glass and a solid resin film arranged on a package lid to coveran OLED device so as to further strengthen the capability of blockingmoisture and at the same lessen a gap in the interior of the sealedobject thereby improving mechanical strength thereof and extending thelifespan and thus making it suitable to a panel of a large size. Thepresent invention provides an OLED packaging method, in which byarranged an inorganic protective frame on an inner side of and, thus,inboard fritted glass, air tightness achieved with the fritted glass iseffectively strengthened. Further, a solid resin film is arranged on apackage lid to cover an OLED device so as to further strengthen thecapability of blocking moisture. Further, the inorganic protective framehelps isolate radiation heat generated in sintering the fritted glassthereby protecting a light emission element from being burned and also,a gap in the interior of the sealed object is lessened to provide asufficient mechanical strength and thus effectively extend the lifespanof the OLED device, making it suitable for a panel of a large size andeasy to carry out with improved operability.

Based on the description given above, those having ordinary skills ofthe art may easily contemplate various changes and modifications of thetechnical solution and technical ideas of the present invention and allthese changes and modifications are considered within the protectionscope of right for the present invention.

What is claimed is:
 1. An organic light-emitting diode (OLED) packagingmethod, comprising the following steps: (1) provides providing asubstrate to be package and a package lid, wherein the package lidcomprises a trough formed therein; (2) coating a loop of frit along acircumference of the package lid outside the trough and applying hightemperature pre-sintering to form fritted glass; (3) forming a loop ofinorganic protective frame on the substrate at a location outside thetrough and corresponding an inner side of the fritted glass, wherein theinorganic protective frame is made of a material comprising siliconnitride, and wherein the inorganic protective frame has an end surfacethat is distant from the substrate; (4) forming an OLED device on aninternal location of the substrate corresponding to the trough of thepackage lid; (5) adhesively attaching a solid resin film inside thetrough of the package lid; (6) forming a loop of adhesive on the packagelid at a location corresponding to the inorganic protective frame; (7)laminating the substrate and the package lid to each other to have thesubstrate and the package lid bonded to each other by means of the solidresin film and the adhesive, wherein the OLED device that is located onthe substrate is completely covered by the solid resin film and locatedwithin an outer circumference of the solid resin film and the inorganicprotective frame is located outside the outer circumference of the solidresin film and is separated from the outer circumference of the solidresin film by a void space around the outer circumference of the solidresin film, and wherein the adhesive is located between the end surfaceof the inorganic protective frame and a surface of the package lid thatfaces the end surface of the inorganic protective frame such that thesubstrate, the inorganic protective frame, the adhesive, and the packagelid are vertically stacked on each other in such an order, wherein theadhesive and the inorganic protective frame are collectively separatedfrom the outer circumference of the solid resin film by the void space;and (8) applying irradiation of laser to melt the fritted glass so as tohave the package lid and the substrate further bonded together tocomplete packaging of the substrate with the package lid.
 2. The OLEDpackaging method as claimed in claim 1, wherein the substrate is athin-film transistor (TFT) substrate comprising a TFT formed thereon. 3.The OLED packaging method as claimed in claim 1, wherein the package lidcomprises a glass board.
 4. The OLED packaging method as claimed inclaim 1, wherein the package lid comprises a metal board.
 5. The OLEDpackaging method as claimed in claim 1, wherein in step (3), theinorganic protective frame has a height that is defined between the endsurface of the inorganic protective frame and the substrate and issmaller than a height of the fritted glass between the package lid andthe substrate.
 6. The OLED packaging method as claimed in claim 1,wherein the solid resin film has a surface area greater than a surfacearea of the OLED device so that when the substrate and the package lidare laminated to each other, the solid resin film completely covers theOLED device.
 7. The OLED packaging method as claimed in claim 1, whereinin step (6), the adhesive is shaped as a circumferential wallcircumferentially co-extensive with the end surface of the inorganicprotective frame so that the inorganic protective frame and the adhesivethat are vertically stacked between the substrate and the package lidform, collectively, a combined circumferential wall that surrounds andis spaced from the outer circumference of the solid resin film and isalso surrounded by and spaced from the fritted glass.